* {
  margin: 0;
  padding: 0;
  font-family: "微软雅黑";
}
a:link,
a:hover,
a:active {
  text-decoration: none;
}
#title {
  background-color: #00bcd4;
  padding: 60px 0px;
  width: 100%;
  text-align: center;
  font-size: 42px;
  color: #fff;
}
.content {
  text-align: center;
}
.intro {
  padding: 20px 0px;
  line-height: 40px;
  font-size: 20px;
}
.intro a {
  color: #00bcd4;
}
.intro a:hover {
  color: #0097a7;
}
.ret {
  display: block;
  text-align: center;
  margin: 30px auto 10px;
  border: 1px solid #ddd;
  background-color: transparent;
  height: 40px;
  line-height: 40px;
  width: 200px;
  border-radius: 10px;
  color: #222;
}
.ret:hover {
  border: 1px solid #888;
}
